A science fan's guide to the Iowa caucus

It must be tricky, sometimes, being a sensible US conservative. You have a reasonable belief in small government, low taxes and the free market. You might have moral stances on family issues or welfare. But, for some reason, it's hard to find a Republican candidate who actually accepts scientific fact.

Of course, it's not any scientific fact – I'm sure they are all quite happy to believe the experts on cosmology or inorganic chemistry. It's really only the facts in two fields: climate change and evolution. The vast majority of relevant scientists believe that the world is warming, that mankind is causing it through emission of carbon dioxide and other gases, and that there is reason to be concerned about it; and that a process of natural selection of heritable traits in varied populations has created all life on Earth from a single origin. But, for reasons that are not completely clear, some conservative politicians on the far side of the Atlantic have difficulty accepting those statements.

So if you're a conservative and a fan of what science has achieved (you know: everything), it must make it quite difficult to pull the voting lever for someone who believes things that are, at best, kooky – a few degrees short of believing that aliens landed in New Mexico in 1948, or that 9/11 was an inside job, but only a few. So here you go: the four leading Republican candidates after the Iowa caucus, in their own words, on climate change and evolution.

Mitt Romney, former Massachusetts governor

Mitt Romney

On evolution:Commendable. “I believe that God designed the universe and created the universe, and I believe evolution is most likely the process he used to create the human body… I believe God is intelligent and I believe he designed the creation. And I believe he used the process of evolution to create the human body."

Further, he didn't duck the "teaching intelligent design in science classes" question: “In my opinion, the science class is where to teach evolution, or if there are other scientific thoughts that need to be discussed. If we’re going to talk about more philosophical matters, like why it was created, and was there an intelligent designer behind it, that’s for the religion class or philosophy class or social studies class.”

On evolution:
Well, he doesn't believe in it. Or he doesn't think it's settled, or something. But he does acknowledge that you can be Christian and still believe in evolution, which is good news for the Pope, at least: "Well, first I thought it was a very inappropriate question, you know, for the presidency to be decided on a scientific matter. I think it's a theory…the theory of evolution and I don't accept it as a theory. But I think the creator that I know, you know created us, every one of us and created the universe and the precise time and manner and all. I just don't think we're at the point where anybody has absolute proof on either side. My personal view is that recognising the validity of an evolutionary process does not support atheism, nor should it diminish one’s view about God and the universe."

On climate change:
Mr Paul is commendably well-informed – he acknowledges that the scientific position is well established, but he is no alarmist. He says on his website: "It is clear that the earth experiences natural cycles in temperature. However, science shows that human activity probably does play a role in stimulating the current fluctuations. The question is: how much? Rather than taking a 'sky is falling' approach, I think there are common-sense steps we can take to cut emissions and preserve our environment. I am, after all, a conservative and seek to conserve not just American traditions and our Constitution, but our natural resources as well."

Rick Santorum, former Pennsylvania Senator

Rick Santorum

On evolution:Mr Santorum pushed the "Santorum amendment", an amendment to the 2001 education funding bill which attempted to push the teaching of intelligent design in science classes, and questioned the validity of evolutionary theory. He told Hardball's Chris Matthews that he only believes in a "some amount" of evolution in a "micro sense". He also told Jon Huntsman, one of the saner voices in the race, that: "If Governor Huntsman wants to believe that he is the descendant of a monkey, then he has the right to believe that."

On climate change (and evolution):He shows a startling lack of even basic understanding, trotting out the old canard of "pure chance" – for the record, evolution by natural selection is thoroughly non-random – and the irrelevant fact that carbon dioxide exists in relatively small quantities in the atmosphere: "Americans don't like being told what to believe. Maybe because we have learned to be sceptical of 'scientific' claims, particularly those at war with our common sense – like the Darwinists' telling us for decades that we are just a slightly higher form of life than a bacterium that is here purely by chance, or the Environmental Protection Agency's informing us last week that man-made carbon dioxide – a gas that humans exhale and plants need to live, a gas that represents less than 0.1 per cent of the atmosphere – is a dangerous pollutant threatening to overheat the world."

Also, while he comes across as quite a likeable chap in interviews, and is clearly honest and principled (if, you know, wrong), he also has the unfortunate problem of the "Santorum neologism". Google it.

Newt Gingrich, former speaker of the House

Newt Gingrich

On evolution:
Another flip-flopper, sort of. "Evolution certainly seems to express the closest understanding we can now have," he told Discover magazine, in a basically accurate if slightly oddly phrased response. "But it's changing too. The current tree of life is not anything like a 19th-century Darwinian tree. We're learning a lot about how systems evolve and don't evolve. Cockroaches became successful several hundred million years ago and just stopped evolving. I believe evolution should be taught as science, and intelligent design should be taught as philosophy."

But then… “Do you think… we’re randomly gathered protoplasm? We could have been rhinoceroses, but we got lucky this week?” He was probably only joking, but it was a bit weird.

On climate change:
Gingrich recently admitted that he "killed" a chapter in his upcoming book which laid out the facts of global warming, by a climate scientist called Katharine Hayhoe, after he was challenged by a listener to Rush Limbaugh's show. “Nice to hear that Gingrich is tossing my climate chapter in the trash,” Dr Hayhoe responded on Twitter. “100+ unpaid hours I could’ve spent playing with my baby.”

But despite that panicky behaviour Gingrich is, like Ron Paul, very well informed on the matter – or at least he was in 2007, when he gave this impassioned talk about the difficulties of reconciling conservatism with conservation: "The evidence is sufficient that we should move towards the most effective possible steps to reduce carbon loading of the atmosphere, and do it urgently. Now. Let me explain why this is a very challenging thing to do if you're a conservative. For most of the last 30 years, the environment has been a powerful emotional tool for bigger government and higher taxes. And therefore, the minute you start hearing these arguments, you know what's coming next: bigger government and higher taxes.

"So even though it might be the right thing to do, you end up fighting it, because you don't want the bigger government and higher taxes, so you end up in these kind of cycles… I think there needs to be a green conservatism. Someone needs to stand up and say 'Here's the right way to solve the problem according to our value system.' And now there needs to be a dialogue about what's the most effective way to solve it, rather than get into a fight over whether or not to solve it."